In recent years, regarding datacenter networks, network virtualization technology utilizing overlay technology such as VXLAN (Virtual eXtensible Local Area Network), STT (Stateless Transport Tunneling), etc. has been gathering attention.
According to VXLAN, which is an overlay technique, a VTEP (VXLAN Terminal End Point) is arranged at an end point of an edge of a VXLAN. A VTEP performs a packet conversion process such as encapsulation of a packet to be transmitted to a VXLAN, decapsulation of a packet received from a VXLAN, etc.
A VTEP operates in accordance with a hypervisor in a physical server. In other words, the packet conversion process is performed by means of software.
In the network virtualization, the encapsulation of packets is performed by means of software, and this has caused performance problems for reasons that a bottleneck occurs due to loads on the CPU (Central Processing Unit) and it is difficult to benefit from the speed acceleration function of an NIC (Network Interface Card), etc.
In the above situation, products that realize higher speeds by conducting off-load of encapsulation/decapsulation processes of packets conducted by software into hardware such as a NIC, a switch, etc. (hardware off-load) are emerging. In other words, these products realize the function of a VTEP by using a NIC or a switch.
At a protocol termination point for network virtualization such as a VTEP, destination node information of packets after encapsulation is obtained from a destination table so as to conduct encapsulation by using the obtained information.
The number of entries in a destination table of a device having an off-load function is very small because of the implementation area and cost. Accordingly, it is difficult to realize a large-scale configuration while using an off-load function.
Furthermore, a document such as Japanese Laid-open Patent Publication No. 2014-160907 is well known.